The present invention relates to a processing technique of fruit pits, especially to a method and device of extracting the liquor from haw pits (herein, it is also referred as to xe2x80x9chaw seedxe2x80x9d).
Haw is a favorited and sour-tasted fruit for many people. They are planted in many northern provinces of China. They can be processed into many kinds of food according to one""s taste. Haw pits, however, have seldom been properly utilized and sometimes they are burned as a fuel. This situation is really a pity.
It has been confirmed by modern scientific methods that liquor extracted from haw pits possesses unexpected anti-bacterial, disinfectant and sterilizing functions. In addition, they have already been widely used in the fields of medicine, hygiene, food processing and environmental protection. For example, external skin disinfectant prepared by using haw pits extract as the raw material does not irritate the skin mucous membrane and does not have any adverse reactions. Mosquito-repellent incense made of haw pits extract possesses good mosquito-killing effect and does not have any undesirable effect to human body. Along with the development of science and technology, the fields of application for haw pits extract would gradually been widened.
Up to now, the technical method for the dry distillation of haw pits such as that disclosed in Chinese Patent Applied No. 96120686.1 described the process of dry distillation of haw pits. Due to the limitation of technological conditions, the efficiency of dry distillation in the said Patent was not high enough and the percentage of corrosive and toxic component of phenol approached 20-25%. For the moment, the widely concerned problems of the manufacturing community are the following: how to utilize reasonable extracting process and simpler manufacturing device to raise the yield of the haw pits extract. At the same time, the undesirable and toxic components of the dry distillation extract should be lowered. These are right problems to be solved by the present invention.
The objective of the present invention is to provide a method of extracting liquor from haw pits by dry distillation, which is simple and have high efficiency of extraction. In addition, the resulting product has very good bacteria-killing property and low content of harmful components.
Another objective of this invention is to provide a device for dry distillation extracting liquor from haw pits.
The method of the present invention for extracting haw pits by dry distillation consists of the following steps:
(1) Removing the impurities from the haw pits and drying the haw pits;
(2) Soaking haw pits in water and putting them into a dry distillation furnace after removing the water by dripping.
(3) In the first substep, raising the temperature within the temperature range of 105-195xc2x0 C. stage by stage and maintaining the temperature at each stage; and in the second substep raising the temperature within the temperature range of 305-380xc2x0 C. stage by stage and maintaining the temperature at each stage; and condensing and collecting the resulting distillate in the two substeps;
(4) Combining the distillates, setting aside for separation by different specific gravities, and separating the brownish red transparent liquid by siphon method.
Since most of the haw pits collected nowadays contain many impurities such as the residual fruit pulp, branches and leaves, coke, coal and garbage, they should be strictly removed in order to ensure the quality of the dry distillation liquor. In the above-mentioned step (1), the impurities can be removed by various methods such as sieving, specific gravity method and chemical method. Generally the pits are dried in natural environment.
In step (2), the haw pits were immersed in water whose volume was 1-2 times of that of the pits for 12-24 hours. Water will swell the pits and will be absorbed by the pits. This can raise the yield of the distillate and can further remove the contaminated soil and other impurities.
In step (3), in the first stage, the temperature of the furnace was raised to 105xc2x0 C. and kept constant for one hour and then successively to 115xc2x0 C., 135xc2x0 C., 155xc2x0 C., 175xc2x0 C., 195xc2x0 C. and kept at each temperature for one hour respectively. In the second stage, the temperature of the furnace was raised to 305xc2x0 C. and kept constant for one hour and then successively to 325xc2x0 C., 345xc2x0 C., 365xc2x0 C. and kept at each temperature for one hour respectively. By so doing, the decomposition of low boiling point distillate can be effectively avoided. When fine particle sand was added into the furnace at an amount of xc2xd to xc2xc by weight based on the weight of the pits, they can improve the heat conduction of the system and raise the efficiency of the dry distillation. Further, the sand can be reused after cleaning.
Dry distillation can be carried out at atmospheric pressure or at reduced pressure. The heat sources used in the dry distillation include but not limited to direct fire or flue gas. And coal (a coal furnace should be installed outside the present furnace when using coal as heat source), coal gas, natural gas or electrical heater can be used to generate heat. Among them, flue gas heating is preferred.
The liquor obtained by dry distillation can be further subjected to fractional distillation. It is preferred to pass nitrogen gas into the fractionated liquor during the fractional distillation to protect the distillate from oxidizing.
The device for dry distilling haw pits of the present invention substantially consists of furnace body, porous inner pipe, eduction pipe, condensing pipe and condenser. The porous inner pipe was inserted into the haw pits, and another end of the porous inner pipe was connected to the eduction pipe. The eduction pipe was connected to the condensing pipe. And then the inner pipe, the eduction pipe, and the condensing pipe formed a passage. From the passage, the distillate obtained by the dry distillation can flow out of the present device.
The inner pipe was a round pipe with porous wall and open ends. It was situated in the center of the furnace and was surrounded by the raw material haw pits. Of course, multiple inner pipes can be placed in parallel and were connected to the eduction pipe and condensing pipe respectively to form a passage for the yield. The condensing pipe used can be of snake form, spiral plate form or butterfly form. The furnace body can be rotated in order to obtain more homogeneous heating and higher heating efficiency.